Plunger actuated underreamer



Jan. 5, 1932. F, 1,839,588

PLUNGER ACTUATED UNDERREAMER Filed Sept. 20-, 1929 2 Sheets-Sheet 1 ment of the cutters. It may be mentioned.

Patented Jan. 5, 1932 UNITED STATES- EDWARD r. RAYMOND, or LONG BEACH, csmronniag'nssrcinon 'ro o -ems, or 7 LOS enemas, o'ALrEon'NiA IPLUNGEBACTUATED UNDERBEAMER Application flled September 20:19.29. Serial F0. 393,953; a

This invention has reference to under'- reamers of thetype in which the cutter assemblies are moved radially to expanded p0 sitions by the action of a vertically movable plunger in the reamer body, it being one put: pose of the invention to provide in a reamer of this character, means for moving the cutters to their expanding positions, or starting with the cutter carriers in expanded post.

tions, means for expanding the cutter sup porting elements, by the action of an object dropped within the drill pipe, such means comprising preferably a plunger adapted to be moved through its cutter expanding move ment by the impact of said object. In another of its aspects, the invention has to do with the provision of means whereby the cutters may be moved to contracted positions to enable the underreamer to be withdrawn through the well casing, without the necessity for returning the plunger to its starting position to accommodate inward radial movehowever that under certain conditions and withcertain types of cutter assembly structures it may e desirable to release the cutters for inward contracting move:

ment from their expanded positions byre- V V v shown in expanded position;

turning the plun er to its correspondingposition, for examp e by way of a suitableconnection therewith through the'drill pipe, but in general I prefer to efiect the radial contacting movement. of the cutters by mount-.

ing them in such a-manner that such move-c ,ment is accomplished by reverse rotational.

movement of the drill pipe, as will be fully explained hereinafter.

The invention may bore, the plunger as mentioned being actuated in its downward movementb an object dropped within the drill pipe. 11 order to allow movement of the cutters to contracted.

positions without the necessity for raising the plunger to accommodate such movement, the

be characterized. more particularly as comprising in its preferred embodiment, a tubular body in which is cutters {are mounted on pivoted carriers whereby they may be swungllaterally on the body from expanded to contracted/positions while the plunger isin its cutter expanding position. Thus in a single operation o'fexpandin g and contracting the. cutters,"the latter may be .moved radiallyg from;onejcon tracted position to expanded. position; and then jswung trom expandedito' anotl lr"ho ly- 1 tracted position Also asi willlllatel: be ex; plained," the cutters mayijfirst befadjiisted .in their swinging contracted positions Tana,

after movement of-ftlieplunger 0 Eipahd theE cutter supporting elements, the

be expanded upon rotationofYthereamen,

The above. features, and additional clifari acteristics of the. invention llw'ill hinder;

stood most readily and clearly. lfrgiri the fol; lowing descriptionof a preferredv .emhodis",

ment of the invention, .reference being had 9 throughout. the. description to 'thefaccom r in gs, nwh h i Fig. ,1 is a generalvie ill stra ill get underreamerfsusp ended a usual drill pipe;

2 is .an enlarged. @inedial eaction. through. the body of the ilnderreamer and one of the. cutter assemblies, the cutter Fig. 3 is a viewsimilarto the cutter infone contracted position; I Fig. 4-.is a section on line H of Fig. 3 Fig, 5,is a section on line 5 5 of 2; Fig. ,6 is aview similar to Figs. Land 5 showingthe cutters in, another contracted: 35 position corresponding to Fig. 9

body. 10, preferably made in a single solid piece, and having the usual tool joint connection at 11with the drill pipe 13. :The body is provided at its lower end with the tool joint box 14 within which pin 15a of the drill bit 15 is threaded to join theunderreamer and Fig. 2 sitting 80 'Fig. 9' is a 'view similar tdFigs. 7 and 8, w

bit for o ration in the usual manner. The body 10 is drilled longitudinally to provide the lower bore 460 and the upper and comparatively longer counterbore 16?). Within the bores is a vertically movable cutter actuating plun er 17 having enlarged and reduced portlons 17a, 17b, and having a substantially slidin fit within the bores 16b, 16a, respectively. T 1e plunger has a central bore 18 through which circulating fluid is delivered from the drill pipe 11 to fluid passages 19 in the drill bit 15. Downwardly tapering conical wedge faces 20 and 21 are formed on the plunger at the lower ends of sections 17a, 176, respectively, these faces being adapted to coact with corresponding wedge faces on the cutter assembly to move the latter radial- 1y outward upon downward movement of the plunger, as willbe described later.

Longitudinal recesses 23 are formed in the sides of the body to take the cutters, the recesses having referably curved sides. 23a, 23b against which the cutters are backed in their two respective contracted positions shown in Figures 4 and 6. At the u per and lower ends of recesses 23, the bo y is cut away to form recesses 24 and 25 which may be of somewhat less depth than recesses 23, and shaped to rovide fiat bearing surfaces and 26 for t e sides of the cutter carrier, hereinafter described, when swung to the respective positions shown in Figs. 8 and 9.

' Radial slots 28 are formed in the body hetween bore 166 and recesses 24, the slots being extended above the upper end of the recesses as at 28 to provide confinement for the upper end of the cutter supporting blocks 29 an pins 300: of cutter carrier heads 30. Radial slots 31 are formed between recesses 25 and the lower bore 16a, and openings 32 are formed in the body below the slots to take the lower ends of the cutter su porting blocks 33 and the pin ends 34a 0 cutter carrier heads 34.

The swinging cutters embodied in the present type 0 reamer may be of any suitable form and character, and it ma be mentioned that although for purposes 0 illustration I show herein a reamer having three swinging cutter assemblies, any other suitable number and arrangement of the cutters may be used. 13 the cutter assembly I refer to the combine cutter and cutter supporting and carrying parts generally indicated at 35, and which in its preferred form embodies the roller cutter 37 mounted on the cutter carrier which comprises the upper and lower heads 30 and 34 and a radially inclined interconnecting stem 37a, which also forms the shaft for roller 37, and the radially movable cutter supporting blocks 29 and 33. The upper supporting block 29 has an inclined conical wedge face 36 adapted to coact with wedge face 20 on the plunger to cause the supporting block and the upper cutter car- 'by their lower pin ends 33a, 34a respectively,

extending in the body slot 32. In the contracted position of the cutter assembly shown in Fig. 3, the upper supporting block 29 has bearing on its inner side against the plunger, the lower supporting block 33 bearing against the body wall 100 at the inner side of the opening 32 and against plunger wedge face 21. Upon downward movement of t 1e plunger to the position of Fig. 2, the cutter assemblies are moved radially outward, preferably to the point of engagement of the cutter carrier head pins with the body at the outer ends of slot 28 and the opening 32. It will be readily apparent that the supporting block structure for each cutter assembly may conveniently be made in one piece should it be desired, for instance b forming a continuous slot (not shown) in the body at 50 between slots 28, and 31, and interconnecting blocks 29, 33 to form a single supporting member for both carrier heads.

The roller cutters together with the carrier heads 30 and 34 thus swing horizontally about the in ends 30a, 34a of the carriers, pin 34a being offset radially inward relative to pin 30a in accordance with the inclination of the cutter from true vertical position, in order to enable the cutter to remain at all positions of its swinging movement in a vertical axial plane of the body. It may be mentioned that insofar as the characteristic rela tive movements between the carrier heads and the supporting blocks are concerned, the

heads may be pivotally mounted on the blocks themselves instead of being journaled in the body. However, for purposes of construction the illustrated pivotal mountin of the cutters in the body is preferred. The outer ends of the blocks preferably have cylindric faces 40 fitted to the inner cylindric ends of the carrier blocks and their in ends, in order to provide maximum sur ace engagement of the carriers within the supporting blocks for all positions of the cutters. As shown in Figs. 8 and 9, in the expanded positions of the cutter assemblies. the straight end faces 41 of the supporting blocks are brought flush with the backing surfaces 26 on the body,

thereby enabling the cutters to swing from III positions of Fig. 3, the relative positions of the cutters within body recesses are as shown in Figs. 4 and 7, the cutters preferably bearing against the curved sides 23a of recesses 23, and appreciable swinging movement of the carrier heads being revented by their engagement with the si es of slots 28 and 31. 'Upon downward movement of the plunger, the cutter assemblies are moved radially outward to the positions of Figs. 2, 5 and 8, as previously described, and to such positions that the carriers are free to swing about their pins to move the cutters to the contracted positions shown in Fig. 9, and in which positions the cutters preferably are brought to bear against sides 23b of recesses 23. [has it will be noted that the cutters have two contracted positions, the one (Fig. 7) in radial alinement with the guide slots when the cutter assemblies are in contracted positions, and the other as shown in Fig. 9 in which the carriers are swung to allowthe cutters to be backed into recesses 23.

The plunger is actuated in its downward movement from the position of Fig. 1 to that of Fig. 2 by the impact of asuitable object shown typically herein as a tubular segment 42 dropped within the drill pipe from the ground level. Preferably a washer 43 of copper or other comparatively soft metal is placed within the upper end of the plunger to deaden the impact or driving force of the tubular segment 42 a ainst the plunger. Although the described expansive movement of the cutter assemblies may be effected bv dropping the plan er itself within the drill pipe, itis referre thatthe plunger be driven throng its cutter expanding movement in the manner described in order to prevent damage to the plunger which might result from its being dropped through the drill pi e. The cutter impelling member 42 being tubular, circulation through the reamer to the drill bit is maintained after the plunger is driven to its lower position.

In carrying out operations, the reamer may be lowered to the working region in the well below casing 44 with the plunger in raised position and with the cutter assemblies in the contracted-position shown in Fig. 7, or with the carrier heads in their outermost radial positions and the cutters swun to the lowered with the cutters swung to contracted positions shown in Fig. 9, expensive movement of the cuttersthereafter being efl'ected by rotation.

Assuming the reamer to be lowered below the casing with the cutter assemblies in the positions of Fig. 3, or with the plunger supported in raised position by the supporting blocks 29, 33, and the carrier heads and cutters swung to the position of Fi 9, the tubular segment 42 is then droppe within the 'drill pipe and upon impact with the upper end of the plunger drives the latter downward to expand the cutter assemblies (Fig. 2) or to move the supporting blocks outward to back up the carrier heads, as the case may be. Upon rotation of the reamer'in clockwise direction as viewed in Fig. 8, the carrier heads are brought to engage the sides 45 of recess 24 to provide rotative backing for the cutters, the radial inward thrust of the cutters being taken by the supporting blocks and the plunger. cutters to enable the reamer to be withdrawn through the casing, the drill pipe is rotated in a reverse direction, counter clockwise as viewed in Fig. 9, whereupon the carrier heads by virtue of their inertia, or by the engagement of the cutters with the well bore wall, are swung to back the cutters into re-- cesses 24. Thus by providing cutter assemblies adapted to be actuated by the plunger to move the cutters from one contracted position to expanded position, and carrier assemblies having such characteristics that the cutters may be swung from their expanded positions to another contracted position without operating the plunger, the necessity is obviated for having to return the plunge to its starting position.

I claim: 1. An underreamer comprising a tubular body connected with the lower end of a drill pipe, a radially movable cutter assembly within a slot in said body. and a cutter operating plunger within the body and having a pair of vertically spaced wedge faces adapted to coact with correspondingly spaced wedge faces on said cutter assembly to expand the latter radially, said plunger being adapted to be actuated by an object dropped within the drill pipe, said cutter o plunger being vertically movable re ative to both the drill pipe and said cutter assembly. 2. An underreamer comprising a tubular body connected with the lower end of a drill pipe, a cutter actuating plunger within said body, a radially movable cutter assembly within a slot in the body comprising, a cutter supporting block having wedging engagement with the plunger, and a cutter carrier at the outside of said supporting block; the plunger being adapted to be actuated by an' object dropped within the drill pipe to In order to contract the move said cutter assembly radially, said cutter operating plunger being vertically movrating able relative to both cutter assembly.

3. An underreamer comprising a tubular body connected with the lower end of a drill pipe, a cutter actuating plunger within said body; said plun erbeing .vertically movable relative'to the rill pipe, :1 radiallymovable cutter assembly comprising, a' air of supporting blocks mounted in vertlcally spaced slots in the body, a'pair'of pivotally mounted cutter carriers bearing against the outside of said supporting blocks, a shaft interconnecting said carriers and a cutter mounted in the. shaft said cutter being capable. of lateral swinging movement relative to the bod) When'said cutter assembly is'moved to its outermost'radial position, and the body being slotted longitudinally to take the cutter the drill pipe and said in itssw-inging movement from expanded to radially contracted position.

4: An .7 underre'amer comprising a tubular body Jconnectedwith the lower end of a drill pipe, a cutter mounted on said body, a radial- 1y movable cutter-supporting assembly comprising means for 'pivota'lly mounting said cutter forl-ateral swinging movement relative to-the' body, an'd'a'plunger within the body for operating said cutter assembly, said plungerbeing vertically movable relative to both said cutter assembly and the drill pipe.

:"-5-.;;:An underreamer comprising a tubular I body-"connectedwith the lower end of a drill pipe, :a'cutter-"mounted on said body, a radially movableflcutter supporting assembly comprisin' means-"for mounting said cutter "for. latera swinging movement relative to the" bod-y,":and awertically movable plunger withinithebod" adapted to be actuated by an object droppe within the drill pipe to move said cutter assembly radially.

.6. An-underreamer comprising a tubular bodyIconnected with the lower end of a drill pipie,:a plunger within said body,'said plunger being vertically movable relative to both said body and-the drill pipe, a'radially movable cutter assembly'withina slot in the body and adapted to be actuated by the plunger, said cutter assembly comprising a cutter supporting block-having wedgin engagement with the plunger and a pivota 1y mounted cutter carrier at the outside of'said supporting block and adapted to swing laterally on the body to swing laterally on the bod to move the cutter between expanded an contracted posi-. tions. 7

8. An underreamer comprising a tubular body connected with the lower end of a drill pipe, a cutter mounted on said body, a radially movable cutter supporting assembly comprising means for pivotally mounting said cutter for lateral swinging movement relative to the body, means-for actuating said cutter assembly to move it from contracted to expanded position, and means confining the cutter against appreciable swinging movement except at substantially the expanded position of the cutter supporting assembly.

9. An underreamer comprising a tubular body connected with the lower end of a drill pipe, a vertically movable plunger within said body, a radially movable cutter assembly within a slot in the body and adapted to be actuated by the plunger, said cutter assembly comprising a cutter supporting block having wedging engagement with the plunger and a pivotally mounted cutter carrier at the outside of said supporting block and adapted to swing laterally on the body to move the cutter from expanded to contracted position, said cutter carrier being confined within said slot against free swinging movement except at substantially the outermost radial position of the cutter assembly.

In witness that I claim the foregoing I have hereunto subscribed my name this 9th day of August, 1929.

EDWARD F. RAYMOND.

move-thecutter from expanded to contracted position. a

7 An underreamer comprising a tubular body connected with the lower end of a drill pipe, a vertically movable plunger within said body and adapted to be actuated by an object dropped within the drill pipe, 9. plunger actuated cutter assembly movable side of said supporting block and adapted top radially within a slot in the body; said cutter assembly 

